[Drake] K2 on TR4C

[Garey Barrell]

Jeff -


1 M is too high.   I'm not sure which relay you're speaking of.  

K1 is the Main T-R relay, 4PDT, and is replaced with a P&B 
R10-E1-Y4-V2.5K.  The original relay was a 15k ohm coil and was prone to 
failure because of the extremely small wire used.  A 1.5k, 1W resistor 
is added in series with the new relay.

K2 is the small relay over by the carrier oscillator crystal, and pulls 
the frequency to within the crystal filter passband for CW.  I think 
this one has a 10k coil, but I've never replaced one so not sure.  It's 
connected in series with the screen voltage divider for V15 and shorted 
by contacts on S-2A(r) [MODE switch] for CAL and SSB.  In the x-CW or 
x-AM mode, the relay pulls in and shifts the Carrier oscillator 
frequency up 1 kHz, moving it into the filter passband.

If the relay is NOT pulling in for CW and AM modes, you can close it 
"manually" and should then get CW output.

73, Garey - K4OAH
Atlanta


jkerby14 at comcast.net wrote:

>    After removing a TR4C from storage K1 and K2 wouldn`t pull in during
>transmit. This problem was chased to a bad V4 , all was well after
>replacement . After a  20 hour burn in of receive only K1 now fails to pull
>in. I still have power in SSB but, none in CW. K1 has the proper supply
>voltage. The coil on K1 is 1.15Mohm. That doesn`t seem right to me. There
>is a full bobbin of some very small wire on it though.Before I frustrate
>myself , has anyone seen this ?
>73 , Jeff  /  N4YU
>
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